The hopper car is a bottom-dump vehicle, is mainly used for transporting granular cargo and discharging the granular cargo from the bottom of the car after the vehicle arrives at the destination.
Due to the long transportation distance and the stronger vibration during the transportation, when transporting valuable and powdery granular cargo with the bottom-dump car, the sealing performance of the bottom door device is very important. A poor sealing performance may result in cargo leakage which causes economic loss, and worst of all, may result in polluting environment and threatening life safety of related person.
FIG. 1a is a schematic view of the structure of a bottom door device of a hopper car in the prior art with the bottom door device in a closed state, and FIG. 1b is an enlarged schematic view of part I in FIG. 1a. The bottom door device includes a first bottom door 1 and a second bottom door 2 arranged symmetrically, both of which are hinged to the hopper car body. The first bottom door 1 includes a first door end plate 11 and a first bottom door plate 12 which are fixedly connected by welding, and the first door end plate 11 is hinged to the car body at position “A”. The second bottom door 2 includes a second door end plate 21 and a second bottom door plate 22 which are fixedly connected by welding, and the second door end plate 21 is hinged to the car body at position “B”. The sealing of the bottom door device is realized by the overlapping between the second bottom door plate 22 and the first bottom door plate 12.
The overlapping sealing way has a strict order requirement for closing the doors; when closing the doors, the second bottom door plate must be closed firstly and then the first bottom door plate is closed; if the doors are not closed in the right order, the bottom door device will have no sealing effect. Thus, in the bottom door device using the overlapping sealing, a driving mechanism must be provided to control the two doors to be closed in the right order, and meanwhile, corresponding parts, for controlling the two doors to be closed in the right order, have to be provided in the control system of the driving mechanism, therefore the bottom door device may have a very complicated structure and a high manufacture cost.